This invention relates to a device for the detection of microorganisms in a fluid sample such as, for example, body fluids. More particularly, this invention relates to a device containing an agar slant as the solid medium in combination with a connection for the device to a liquid medium culture bottle or container. The device provides for proper exposure of the two media to the sample under investigation while at the same time providing complete non-covered access to the solid agar slant. Thus, once the microorganisms have been grown, they may be examined directly without any glass or plastic covering interfering with the examination.
In the detection of microorganisms in body fluids, particularly bacteria in blood, there is a requirement that a sample of the fluid be used to inoculate a liquid nutrient medium. Subsequent to this, the liquid medium is in turn used to inoculate a solid medium to continue the growth of the organisms. Generally, devices have been provided in which both the liquid and the solid culture media are combined in the same container. This overcomes any problems involving exposure during transfer of these cultures in the liquid medium to the solid culture medium in another container. Representative of such devices is that described in U.S. Pat. No. 3,589,983, issued June 9, 1971. Other patents directed to the subject matter of the invention include U.S. Pat. No. 3,651,926, issued Mar. 28, 1972 and U.S. Pat. No. 4,308,347, issued Dec. 29, 1981.
There are problems, however, with combined devices in that the constituents of the solid medium may be dissolved in the liquid medium. Thus, only solid media compatible with the liquid medium can be utilized. If the solid media constituents pass into the liquid medium, differentiations of the pathogens may no longer be possible.
With the present invention, the solid medium and the liquid medium are appropriately separated, but may be connected together in order to provide the proper exposure of the solid medium to the liquid medium containing the sample under consideration. Nevertheless, once the inoculation period has taken place, the device of the invention may be disassembled to the extent whereby the solid medium agar slant may be examined completely and directly without any interference from some covering therefor.
That is, the device of the invention includes a base structure supporting an agar slant, for example. The base structure includes a connection for connecting the base structure to a liquid culture medium container. The base structure carrying the agar slant, which has the solid medium contained thereon, has a complete covering or cap for covering the solid medium in a liquid-tight connection so that once the sample has been introduced into the liquid medium container, the device of the invention may be connected thereto and the agar slant or solid medium may be exposed to the liquid medium containing the sample of interest.
Nevertheless, the exposure is only intermittent, as required and desired, in order to provide the appropriate culture development during the inoculation period, with proper removal of the liquid medium, intermittently, in order to allow the culture to take place on the solid agar slant. Once the inoculation period has taken place, the entire cover on the device may be removed so that the entire agar slant and/or solid media with the cultured organisms present thereon may be exposed for complete examination by the laboratory technician.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.